When I sold off my 300 gallon tank pending a move to a new house I had this same experience. My son and I helped the purchaser and his friend get all the rock into bins. Just the action of moving the several year old and paly covered rocks was enough to cause the toxin to release. My son, who hadn’t even touched the rocks, and I who wore gloves, were also sickened. This was from breathing the toxin rather than absorption. The new owner and his friend suffered even more as they had handled the rock with bare hands. You probably hear a lot about palytoxin in the hobby, maybe not, but it is something you should be aware of. Palythoa are some of the easier to grow corals and are often had by beginners, those without a lot of knowledge and experience. After getting so ill (dangerously so) I decided not to own paly again. My current two tanks have none and I have no plans to include them in the future.
In the process he took out a rock covered in coral and scraped it clean.Inadvertently he released deadly substance palytoxin into the atmosphere, and then closed the door and went to sleep.The following day the entire family suffered flu-like symptoms, and even their two dogs became ill.Chris suffered breathlessness, coughing and fever which he said was ‘as bad as pneumonia’.
Source: Tropical fish owner almost killed family after coral released deadly fumes | Daily Mail Online